TCRC Monthly Seminar Series Presents: “Post-transcriptional Regulation of the Cardiac Proteome”

Alternative splicing (AS) presents a major source of proteoform diversity. However, whereas transcriptomics studies have cataloged extensive isoform variations, their translation into functional proteoforms and regulatory states, in particular regulation under stress and disease conditions, remains poorly defined at the protein level. Many splicing events alter intrinsically disordered and regulatory regions, suggesting that AS may shape proteoform-specific responses to stress and influence protein organization within the cell.

In this seminar, we will report on a strategy to extend beyond the limitations of trypsin-based bottom-up proteomics, where splice junction peptides are often poorly captured, integrating a middle-down proteomics approach to improve detection of alternative proteoforms and resolve combinatorial post-translational modifications. This approach greatly expands the detection of alternative protein isoforms and reveals coordinated regulation of isoform expression and post-translational modifications under stress conditions. The findings support a model where alternative splicing is dynamically regulated by proteoform-level modifications and compartment-specific factors, revealing mechanisms that potentially shape splicing outcomes across cellular environments.